Auckland is a large metropolitan city in the North Island of New Zealand. It has an urban population of about 1,530,500 (June 2024). It is located in the greater Auckland Region, the area governed by Auckland Council, which includes outlying rural areas and the islands of the Hauraki Gulf, and which has a total population of 1,797,300 as of June 2024. It is the most populous city of New Zealand and the fifth-largest city in Oceania.

The city lies between the Hauraki Gulf to the east, the Hunua Ranges to the south-east, the Manukau Harbour to the south-west, and the Waitākere Ranges and smaller ranges to the west and north-west. The surrounding hills are covered in rainforest and the landscape is dotted with 53 volcanic centres that make up the Auckland Volcanic Field. The central part of the urban area occupies a narrow isthmus between the Manukau Harbour on the Tasman Sea and the Waitematā Harbour on the Pacific Ocean. Auckland is one of the few cities in the world to have a harbour on each of two separate major bodies of water.

The Auckland isthmus was first settled c. 1350 and was valued for its rich and fertile land. The Māori population in the area is estimated to have peaked at 20,000 before the arrival of Europeans. After a British colony was established in New Zealand in 1840, William Hobson, then Lieutenant-Governor of New Zealand, chose Auckland as its new capital. Ngāti Whātua Ōrākei made a strategic gift of land to Hobson for the new capital. Māori–European conflict over land in the region led to war in the mid-19th century. In 1865, Auckland was replaced by Wellington as the capital, but continued to grow, initially because of its port and the logging and gold-mining activities in its hinterland, and later because of pastoral farming (especially dairy farming) in the surrounding area, and manufacturing in the city itself. It has been the nation's largest city throughout most of its history. Today, Auckland's central business district is New Zealand's leading economic hub.

While Europeans continue to make up the plurality of Auckland's population, the city became multicultural and cosmopolitan in the late 20th century, with Asians accounting for 34.9% of the city's population in 2023. Auckland has the fourth largest foreign-born population in the world, with 39% of its residents born overseas. With its sizeable population of Pasifika New Zealanders, the city is also home to the largest ethnic Polynesian population in the world.

The University of Auckland, founded in 1883, is the largest university in New Zealand. The city's significant tourist attractions include national historic sites, festivals, performing arts, sports activities and a variety of cultural institutions, such as the Auckland War Memorial Museum, the Museum of Transport and Technology, and the Auckland Art Gallery Toi o Tāmaki. Its architectural landmarks include the Harbour Bridge, the Town Hall, the Ferry Building and the Sky Tower, which is the second-tallest building in the Southern Hemisphere after Thamrin Nine. The city is served by Auckland Airport, which handled 18.5 million passengers in 2024. Auckland is one of the world's most liveable cities, ranking fifth in the 2024 Mercer Quality of Living Survey and at ninth place in a 2024 ranking of the Global Liveability Ranking by The Economist.

The Māori-language name for Auckland is Tāmaki Makaurau, meaning "Tāmaki desired by many", in reference to the desirability of its natural resources and geography. There are various theories of the origin of the name "Tāmaki", which is also used to refer to an eastern suburb of Auckland. It is regarded by some to be the isthmus between the two harbours of the area, which is variously said to be named after a son of Maruiwi from Taranaki, a line of chiefs from the southern Taranaki, or a female leader of Ngāti Te Ata. Other versions of the name include Tāmakinui (great Tāmaki) or Tāmaki-herehere-ngā-waka (Tāmaki that binds many canoes).

William Hobson named the area after George Eden, Earl of Auckland, British First Lord of the Admiralty. The Earldom of Auckland was named after West Auckland, a village in County Durham, Northern England. The name "Auckland" in West Auckland is thought to originate from the Cumbric word "Alclud", which was the Kingdom of Strathclyde's alternative name meaning "cliff on the Clyde". It is thought 'Clyde' may be the river Gaunless' old name.

Auckland is popularly nicknamed the "City of Sails" or the "Queen City".